Dell 5424 Switch segregate incoming internet connections

I have a separate cable internet connection coming in to a single port on my Dell 5424 switch. I need to keep this separate from all other traffic and restrict it to a single appliance. The Cable connection comes into the Dell switch (port 3) and needs to go to our Cisco switch via the fiber connection. The appliance is connected to port 6 on the Cisco switch. I have the appliance configured with the proper static IP provided by the cable company along with Gateway and DNS and works connected directly but I need this at the other end of the building going through these two switches to get there.

Thank you